1. Technical Field
The present invention relates to an electro-optical device.
2. Related Art
In recent years, a head mounted display has been receiving attention (for example, refer to JP-A-2007-219106).
In such a head mounted display, when an image is smaller than the diameter of the eyes, it is required that a display position of the image be strictly adjusted to the position of the eyes, and thus, convenience deteriorates. For this reason, it is required that image light be spread so as to be larger than the diameter of the eyes. In addition, in the head mounted display, it is required that light having the same intensity distribution be incident on both the right and the left eye. For this reason, as illustrated in FIG. 12, it is desirable that an emitted beam be uniform and be spread by using a layered body 60 which includes a long plane-parallel plate 61, a half mirror 62, and a total reflection mirror 63.
In addition, an optical element, which causes non-uniform light intensity distribution to be uniform and changes an aspect ratio of the beam, is known (for example, refer to JP-A-7-325267).
However, when the above-described layered body 60 is employed, the emitted beam is discharged in many directions. For this reason, when necessary light is selected and the image light is generated on a light emitting surface side, it is required that an additional light shielding countermeasure be installed at a separated position. For this reason, the configuration of the device becomes unnecessarily large, and thus, there is a problem of contrast ratio deterioration due to stray light which cannot be prevented by increasing the cost or installing the light shielding countermeasure.
Here, it is possible to consider combining the light having an angle distribution, like the image light, with the technology in the above-described JP-A-7-325267. However, since light which is determined in a first direction is assumed to be light which is incident at 45 degrees in the technology of the above-described JP-A-7-325267, the stray light is generated similarly to a case where the above-described layered body is used.